Impersonate user with google calendar API oauth2 service account (node.js)

Question

I am trying to use a server for server authentication through the google calendar API. In the documentation they mention you can impersonate a user. I have added owner permissions to the account I want to impersonate and made sure the domain-wide delegation is enabled. From what I have read, the 'user@example' should specify the impersonator, but it does not work. I have all the functions of creating events etc working, but I can't get it to be from an email other than the randomly generated google one.

Here's my code:

var google = require('googleapis');
var calendar = google.calendar('v3');
var scopes = ['https://www.googleapis.com/auth/calendar'];
var key = require ('./xxx.json'); // private json
console.log("Calendar Service connected");
var jwtClient = new google.auth.JWT(
  key.client_email, 
  null, 
  key.private_key, 
  scopes,
  'user@example.com'
);
jwtClient.authorize(function(err, token) {
  if(err) { 
    //console.log(err);
  }
  console.log('token',token);
  //listCalendars(jwtClient);
});

module.exports = {};

Answer 1

I got it to work after:

1. Enabling domain-wide delegation
2. Adding user to the service account as the owner
3. Most importantly: Going onto google admin and giving api access to the service account